The press is not immune from entanglement in such probes, but the broad scope of the records seized from the AP sent a deep chill through the press corps.
A free press is essential to a free society.
"Justice Department regulations call for subpoenas for journalists' phone records to be undertaken as a last resort and narrowly focused, subject to the attorney general's personal signoff," the New York Times said.
"Under normal circumstances the regulations call for notice and negotiations, giving the news organization a chance to challenge the subpoena in court."
Machen's spokesman, William Miller, acknowledged that, saying "We must notify the media organization in advance unless doing so would pose a substantial threat to the integrity of the investigation."
There was no such notification in this case, which may mean that the department has a pretty big fish on the line.
Time will tell.
The press isn't apparently the target of this investigation; the leaker is.
But the press will - and should - remain vigilant about protecting its right to obtain information about what the government is doing.
The secret seizure of records - without notice - is a threat not just to reporting, but by extension to all Americans.